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Real air conditioning (not swam cooler)

Started by VanDreamer, September 18, 2018, 01:55:02 AM

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VanDreamer

Is it possible to run a "real" air conditioner in a van conversion? I know it's easy to get a 5,000 BTU air conditioner that cools a room in a house but it seems difficult to find anything smaller - that would be an overkill in a van and huge power hog. I wish something like 500-1,000 BTU existed but I'm having hard time finding one. Has someone done this successfully?

Camper_Dan

Greetings and Welcome!

You might be going the wrong direction on this,  don't most factory campers have 12k-16k BTU A/C's in their small ones?  Remember that a van is MUCH harder to cool than a room in a house.

With shore power or a generator it can be done, solar and batteries isn't practical, cost or weight efficient. 

What's your objections to the several more popular and more efficient battery powered options?

Cheers!
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VanDreamer

I will be getting a Dodge or Mercedes sprinter van, not a pre-built camper van that comes with A/C. It's frustrating that the technology exists, but not the amount of BTU / power usage I want. The only 1,000 BTU coolers I've found are for cooling computer servers and cost thousands :(


Camper_Dan

Greetings!

Even a 5,000 BTU air conditioner is going to struggle hard in a sprinter, especially if you're parked in the sun for solar to work.

I only know of several cost effective and energy efficient systems that will work:

A) Direct Swamp Cooler
B) Indirect Swamp Cooler (What I use)
C) Ice powered air cooler
D) Peltier powered, circulated cold water through a radiator with a fan.

My indirect type swamp cooler works really well even in high humidity, and is 12v and only uses 3 amps on high, and 1.5 amps on low which is where it is normally set.

I also have peltier powered seat cushions that both heat and cool.  They use 2.5 - 5 amps @ 12vdc.  They heat or cool a liquid that is pumped through tubes in the seat cushions.  They work REALLY WELL.  I use one on my bed as well.  They have a temperature adjustment on them, and have the capacity of making you too hot or too cold.

Just the peltier seat cushions would normally be enough for me, but since I am sometimes in really humid areas, my swamp cooler helps dehumidify my van, which I find quite helpful.

Side by side with similar sized camper vans, my neighbor was running a generator to power a 12k BTU air conditioner, and we were hanging out in my van with my swamp cooler because it was so much nicer than in his van.  We were both parked in the sun, him by choice for his solar panels, and me begrudgingly because there were no spots in the shade.

If you're using them properly, swamp coolers or peltier coolers are hard to beat.  Ice coolers require ice, swamp coolers require water, and the peltier coolers don't require either.  The best part is they are all low power draws at 12 volts.  Personally I think trying to run power hog air conditioners is just plain foolish, when you can build or buy low cost, low power stuff that will work even better.  I think my swamp cooler cost me all of about $60 to build.

My store bought peltier seat cushions from a truck stop were expensive, like $120 each, but... I REALLY love them.  I bought one, and liked it so well I went back and bought more.  About 10 years later, they're working perfectly, and I use them quite a lot if it's really hot or really cold out.

The peltier air conditioners work the same way my seat cushions work, except the heated/cooled solution is circulated through a radiator with a fan circulating the air through the radiator.  Basically the peltier replaces the ice, or the exaporative cooling of the circulating water/solution.  The type I'm talking about is NOT the type that tries to directly cool the air.  The peltier heats/cools a liquid.

If you're still determined that you want "REAL" air conditioning, you could build an off grid gas/diesel/propane powered unit using a gas engine, and the same components in a car air conditioner.  These are popular with off gridders that don't know about the better options available.

I found this on Google:

"According to electricity expert Michael Bluejay, the average refrigerator uses 488 BTUs per hour in normal use. Your car Air Conditioning is about 5 Tons (60,000 BTU) at highway speeds. Yes sixty-THOUSAND BTU, not a typo.Jul 18, 2014"

Cheers!
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Pass them on!!!

VanDreamer

Camper_Dan, thank you so much for your thorough answer. After doing some research, it really looks like running an actual AC is just not going to happen. I'll try some methods that you propose, your ideas are GREAT. I have time, my main goal is to take the van to Burning Man 2019 where cooling a vehicle is challenging. This year it got to 102 degrees and it was MUCH cooler than last year which was hell on earth between 10am and 7pm  :-\ - must've been 110 degrees, maybe more.

Thanks again! I'll post my findings here, maybe someone will find them useful later.

Camper_Dan

Greetings!

For Burning Man, the cooler of choice seems to be the direct style of swamp coolers.

For these to work the most efficiently, you need outside air going into it, then it blows that directly into your rig, and you need ventilation on the opposite end of the rig.  This method replaces the hotter air with cooler air, rather than trying to cool the hotter air.  Very efficient in drier climates, and the slight addition of moisture to the air is actually beneficial for your overall comfort.

Use something like a 10" O2-Cool or Road Pro fan, or even an electric radiator fan.  You'll want a fair amount of air movement in those temperatures.  Also try to create shade for your van, that can help immensely as well.

My indirect swamp cooler works at Burning Man too, but it takes longer to cool it off to begin with because instead of replacing the hot air, it is cooling the hot air.  This method allows it to work in high humidity areas as well, but is not the most efficient or quickest method in desert areas.

Cheers!

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Pass them on!!!

VanDreamer

Camper_Dan, if you don't mind me picking your brain a little bit more, I've looked into swamp coolers and this is where my brain crashes LOL - if my van air is cooler inside than it is outside, most instructions for swamp coolers tell me to pull hot air from inside and cool it via evaporation. Would it not make sense to circulate the air inside and cool the cooled air even further by evaporating more water? It just sounds weird to pull in hot air. Some cooler instructions rave how the swamp cooler drops the temperature by 20 degrees. Well if it's 110 degrees outside in Nevada desert, cooling the air to 90 degrees is not exactly a victory of epic proportions. Yes it helps but it's still hot.

Ice can be purchased at Burning Man so melting ice sounds like a better idea, I don't know? The topic is a little confusing. My initial thought was to just get a generator and blast AC. Some people say it works at Burning Man, others tell the generators fail due to high altitude (thin air, generator doesn't produce as much power) and/or dust in the engine. Also there are a lot of RVs with generators running all the time so I'm sure a lot of people still use it successfully.

Camper_Dan

Greetings!

Swamp coolers can actually cool up to 50 degrees or more if they're implemented right.  I've successfully got my interior temperature down to 70 degrees when it was 120 degrees outside.

Direct type swamp coolers add moisture to the air during the evaporation process.  If you're pulling in outside air, and exhausting it out the other end of the vehicle, the moisture/humidity level isn't an issue.  If you recirculate the air, it just keeps raising the humidity until it quits working.

An indirect swamp cooler does recirculate the indoor air, but both the intake and the exhaust from the evaporation process are routed to the outside.

Both styles require outside air for the intake.  The temperature of the outside air doesn't seem to matter.

While some of the ice versions do work, they can go through a lot of ice in those temperatures.  The good ones are also more complicated to make, and require a radiator like my indirect swamp cooler does.  The direct style swamp coolers are probably the easiest to make, and can be made in numerous configurations.  Some people build them into ice chests, and some people even build them into 5 gallon buckets up to huge garbage cans.  Many people put the coolers themselves outside, then run a hose inside.  For both security and stealth, I prefer to have my cooler inside because I don't like tempting thieves.

At 4,000 ft elevation, that shouldn't be an issue for generators, now the playa dust, that's a whole different story.  It could clog air filters or worse if  it gets into an engine.

I kind of like units that will fit in a front window, since that is the biggest opening windows, and if they're portable, they can be taken out and the window easily rolled up.  Some people replace a back window with an a/c or swamp cooler, but I don't like design as well.  There's more complicated ways too, but they involve cutting holes in walls, and I don't like that idea much.

I'm not much of an artist, but here's the basics of how a direct type swamp cooler works.




Cheers!
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Pass them on!!!

VanDreamer

Hello and thanks for the ideas again. I actually bought a small swamp cooler from Amazon for Burning Man 2018 and I tested it at home. It died after testing it for 4 hours and I returned it. The air flow from it was pretty minimal also.

Also couple of years ago I built a small swamp cooler but in hindsight the fan was not powerful enough and the area to be cooled was too big (large tent) - it did nothing. Maybe that's why my faith in swamp coolers is limited.

I'm now experimenting. I got 2 high air flow CPU case fans and an infrared thermometer from Amazon. I'm going to test various materials and figure out with the thermometer what gives me the best evaporation and as a result, most powerful cooling.

Camper_Dan

Greetings!

Computer fans aren't going to cut it, you need something like a 10" O2Cool or Road Pro fan, or an electric radiator fan.  Direct swamp coolers require a large amount of air movement to be effective, especially in a Burning Man type environment.  A vehicle is harder to cool than a room in a house. 

It's also helpful to understand how the different coolers work.  A direct swamp cooler cools the air by replacing the hot air with cooler air, while all of the other types actually cool the hot air by recycling it.    Replacing the hot air is much quicker than cooling it.  That's why in dry environments, direct swamp coolers are the most effective air conditioning you can get, even better than compressor air conditioners.

Cheers!
Smiles are extremely contagious,
Pass them on!!!